JDBC常用代码
try { //加载驱动 Class.forName("com.mysql.jdbc.Driver"); String url="jdbc:mysql://127.0.0.1:3306/test"; //通过DriverManager获取连接 Connection conn=DriverManager.getConnection(url,"root","hello"); System.out.println("conn:"+conn); //准备操作数据库 //Statement:用于执行静态SQL语句并返回它所生产结果的对象 Statement stm=conn.createStatement(); String sql="insert into test.new_table(t1,t2) values('t11','t22');"; Boolean ret =stm.execute(sql); conn.close(); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); }
package com.wzh.JDBC; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; /* * 连接工厂 * 从面向对象的角度来说,凡是连接相关操作都给这个对象处理 */ public class ConnectionFactory { private static final String URL="jdbc:mysql://127.0.0.1:3306/test"; private static final String USER="root"; private static final String PASSWORD="hello"; private static final String DRIVER="com.mysql.jdbc.Driver"; /** * 获取数据库连接 * @return 成功返回 java.sql.Connection * 失败返回NULL * */ public static Connection GetConnection(){ try { Class.forName(DRIVER); return DriverManager.getConnection(URL,USER,PASSWORD); } catch (Exception e) { System.out.println("%%%%%%%%%%%% 获取连接错误 %%%%%%%%%%%%%%"); e.printStackTrace(); return null; } } /** * 关闭数据库资源 * @param conn * @param stm * @param rs */ public static void Close(Connection conn,Statement stm,ResultSet rs) { try { if(conn!=null) conn.close(); if(stm!=null) stm.close(); if(rs!=null) rs.close(); } catch (Exception e) { System.out.println("%%%%%%%%%%%% 关闭连接错误 %%%%%%%%%%%%%%"); e.printStackTrace(); } } }
PreparedStatement 用法:
Connection conn=null; PreparedStatement stm=null; ResultSet rs=null; try { //加载驱动 conn= ConnectionFactory.GetConnection(); System.out.println("conn:"+conn); //准备操作数据库 //Statement:用于执行静态SQL语句并返回它所生产结果的对象 String sql="select * from new_table where t1=? and t2=?"; stm=conn.prepareStatement(sql); stm.setString(1, "1"); stm.setString(2, "aa"); System.out.println("sql:"+sql); rs =stm.executeQuery(); while(rs.next()){ System.out.println(rs.getString("t1")); System.out.println(rs.getBoolean("boo")); } System.out.println(rs); conn.close(); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } finally{ ConnectionFactory.Close(conn, stm, rs); }
Statement 用法:
Connection conn=null; Statement stm=null; ResultSet rs=null; try { //加载驱动 conn= ConnectionFactory.GetConnection(); System.out.println("conn:"+conn); //准备操作数据库 //Statement:用于执行静态SQL语句并返回它所生产结果的对象 stm=conn.createStatement(); String sql="select * from new_table"; rs =stm.executeQuery(sql); while(rs.next()){ System.out.println(rs.getString("t1")); System.out.println(rs.getBoolean("boo")); } System.out.println(rs); conn.close(); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } finally{ ConnectionFactory.Close(conn, stm, rs); }